By U.S. Patent Application Publication No. 2007/0065240 A1, a united kit of a plurality of cutting inserts or cutting insert blanks is previously known, which can be separated one by one from the kit via indications of fracture. More precisely, the kit has the form of a magazine formed of a plurality of cutting inserts that are arranged in a row one after the other and can be fed forward one after the other into an active position in a tool body in the form of a boring bar, and that, after having been consumed by chip removing machining, are separated by breaking a weak connection member in order to, in such a way, give room for a trailing, unused cutting insert. This cutting insert kit is, however, associated with a plurality of disadvantages and limitations as a consequence of the fact that the different cutting inserts are interconnected, more precisely via connection members, which connect the rear end of each front cutting insert with the front end of a cutting insert being behind. In doing so, the connection member is located along the under sides of the cutting inserts, while the requisite cutting edge is formed in the transition between the upper side and a front clearance surface. Because the cutting edge has to be formed in the same front end that, via the connection member, connects the cutting insert to each cutting insert being in front, the latitude of the designer is significantly limited to construct the part of the active cutting insert that protrudes from the tool body, in different designs and with different cutting geometries. For instance, manufacture of double-sided cutting inserts is made impossible, i.e., cutting inserts that include operable cutting edges along the upper side as well as the under side. Also, the manufacture is limited to positive cutting inserts, i.e., cutting inserts the cutting edge angle of which between the chip surface and the clearance surface is acute, because otherwise, the remains of the broken-off connection member would interfere with the clearance of the cutting insert from the generated surface in the workpiece.
A cutting insert kit of the initially generally mentioned kind is furthermore known by DE 750725. However, also in this case, the cutting insert blanks included in the kit are mutually connected.
The present invention aims at obviating the above-mentioned disadvantages and limitations of the known cutting insert kit and at providing an improved cutting insert kit.
An object of the invention to provide a cutting insert kit, which offers the designer a great latitude to give the included cutting insert blanks most varying shapes. Among other things, it should be possible to form the individual insert blank with at least two useful cutting edges. In addition, it should be possible to manufacture the cutting insert kit by conventional pressing and sintering techniques, which allow at least the upper side and preferably also the under side to be formed with chip breakers or other formations included in topographically sophisticated chip surfaces.
Another object of the invention is to provide a cutting insert kit, which can be realized not only with identical cutting insert blanks but also with cutting insert blanks that are disparate, e.g., in respect of cutting geometries, corner radii, etc.
Yet another object of the invention is to provide a compact cutting insert kit that can be transported, stored and handled in a simple and convenient way.
Still another object of the invention is to provide a cutting insert kit, the indications of fracture of which result in minimal and harmless remains on the separated cutting insert.
Still another object of the invention is to provide a cutting insert kit, which in connection with the manufacture can be formed with a reliable and exact clamping of the separated cutting insert in the appurtenant tool holder, e.g., a boring bar.
Still another object of the invention is to provide a cutting insert kit from which double-sided, i.e., multi-edge, cutting inserts should be separable, which simplifies the work to invert the cutting insert and change the cutting edge, more precisely in such a way that the user in a structured way should be able to keep track of which cutting edge is unused.